In the wake of the storm

In the wake of Hurricane Katrina, Michael Leavitt, Secretary of Health and Human Services, said a public health emergency warning was in place from Louisiana to Florida. He said there were grave concerns about cholera, typhoid and dehydrating diseases.

Mr. Leavitt's warning may have missed the mark, however; outbreaks of diseases such as cholera and typhoid are not probable because the microbes which carry them are virtually non-existent in the US, and so an outbreak like the one in West Africa is very unlikely.

The Centers for Disease Control and Prevention (CDC) records from previous US disasters show the majority of medical problems after the events have been associated with diarrhoea and asthma. The CDC and the Food and Drug Administration are advising people to throw away food that may have come into contact with flood water and only to drink bottled water.

Dr Glenn Morris, a professor of epidemiology at the University of Maryland Medical School in Baltimore, said: "The biggest problem is the sewage contamination of the water. Just splashing around in the water, if there is sewage contamination there is a risk you could get it on to your hands and get it into your mouth." He said viruses such as hepatitis A could be a threat as well as dangerous strains of E.coli.

As many wild animals have been pushed from their normal habitats into limited dry areas (and hence into closer contact with people), rabies may become a problem. Another problem may be mosquito-borne diseases, such as West Nile Viral Encephalitis. Stagnant flood waters may result in a booming mosquito population. WNVE killed more than 200 people in the US in 2004.

Fortunately, these diseases are not directly transmitted from person to person, and so as the water recedes and order returns to the area, any disease outbreak should die off quickly.

Tags: Katrina, Hurricane Katrina, disease, Health